Surface ClusterVersion RetrievedUpdates condition messages

Description of problem:

Since way back in 4.8, we've had a banner with To request update recommendations, configure a channel that supports your version when ClusterVersion has RetrievedUpdates=False . But that's only one of several reasons we could be RetrievedUpdates=False. Can we pivot to passing through the ClusterVersion condition message?

Version-Release number of selected component (if applicable):

4.8 and later.

How reproducible:

100%

Steps to Reproduce:

1. Launch a cluster-bot cluster like 4.11.12.
2. Set a channel with oc adm upgrade channel stable-4.11.
3. Scale down the CVO with oc scale --replicas 0 -n openshift-cluster-version deployments/cluster-version-operator.
4. Patch in a RetrievedUpdates condition with:

$ CONDITIONS="$(oc get -o json clusterversion version | jq -c '[.status.conditions[] | if .type == "RetrievedUpdates" then .status = "False" | .message = "Testing" else . end]')"
$ oc patch --subresource status clusterversion version --type json -p "[{\"op\": \"add\", \"path\": \"/status/conditions\", \"value\": ${CONDITIONS}}]"

5. View the admin console at /settings/cluster.

Actual results:

Advice about configuring the channel (but it's already configured).

Expected results:

See the message you patched into the RetrievedUpdates condition.